Valve gear for multiple cylinder steam engines or pumps



P 1944- w. J. REDMAN ETA-L 2,359,269

VALVE GEAR FOR MULTIPLE CYLINDER STEAM ENGINES 0R PUMPS Filed Feb. 23, 1942 4 Sheets-Sheet l Gib GD GD- GD GD F'IEI 1- Sept. 26, 1944. I w. J. REDMAN ETAL 2,359,269

VALVE GEAR FOR MULTIPLE CYLINDER STEAM ENGINES 0R PUMPS Filed Feb. 23, 1942 4 Sheets-Sheet 2 VALVE GEAR FOR MULTIPLE CYLINDER STEAM ENGINES 0R PUMPS Sept. 26, 1944. w. J..REDMAN EI'AL 4 Sheets-Sheet 3 7 Filed Feb. 23, 1942 [7606 2210745.- W/ALMM EEDMAW m/ JOHN M @fl/MEE,

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Sept. 26, 1944. w. J. REDMAN ET AL 2,359,269

VALVE GEAR FOR MULTIPLE CYLINDER STEAM ENGINES OR PUMPS Filed Feb. 25, 1942 4 Sheets-Sheet 4 Patented Sept. 26, 1944 VALVE GEAR FOR MULTIPLE CYLINDER STEAM] ENGINES OR PUMPS William J. Redman, Braddock, Pa., and John M. Shimer, Dallas, Tex., assignors to Oil Well Supply Company, a corporation of New Jersey Application February 23, 1942, Serial No. 432,088

3 Claims. (01. 121 11e Our invention relates to improvements in multiple direct acting steam engines, pumps and the like, and includes an improved valve gear therefor.

In rotary well drilling, fluid mud is pumped down the drill pipe to the rotary bit and the cuttings are thereby forced or flowed upwardly out of the well. Duplex steam pumps have been standard equipment for such purposes, but due to the increased depths of drilling today, some difficulty has been experienced in obtaining the desired efficiency and depth capacity with such pumps. Duplex pumps have been compounded by connecting the same in series or parallel for said purposes, but such arrangements are both expensive and cumbersome.

' It is a prime object of this invention to provide a direct acting pumping unit for heavy duty, capable of producing high pressure without compounding and having a large volumetric capacity.

Another object is to provide a pump of the character stated which will have weight and proportions comparable with present pumping equipment so as to provide maximum portability in the field.

A further object is to provide a multiple cylinder pump of more than two cylinders having a full stroking smooth action, capable of developing a constant fluid discharge pressure without pounding or pulsations in the discharge lines.

A still further object is to provide a positive acting steam valve gear for such a pump having perfect timing, effecting rapid reversal of stroke and possessing self-balancing or governing properties to compensate for variations in load upon the multiple cylinders.

We have in view to provide a pumping unit having the foregoingcharacteristics and properties by employing a multiple cylinder pump whose cylinders are operable in sequential relation with overlapping strokes, and have found that such an arrangement can be successfully and efficiently operated without short stroking, pounding or other objectionable features encountered in other direct acting pumps heretofore.

Additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a plan View of a multiple cylinder direct acting pump embodying our invention;

Fig. 2 is a cross section thereof, taken on the line II -II of Fig. 1, particularly showing one cylinder with its associated valve gear;

Fig. 3 isa cross section taken on the line III-III of Fig. 1, particularly illustrating the multiple steam valve gear; and

Fig. 4 is a diagrammatic view schematically illustrating said valve gear and the valve motion for the plurality of steam cylinders.

Referring to the drawings, the multiple direct acting pump illustrated includes a steam end A comprising three steam cylinders A1, A2 and m, and a fluid or mud end B, the latter having three fluid cylinders B1, B2 and B3, respectively aligned with said steam cylinders. The steam end A may be formed of a casting including valve chests C1, C2 and 03 for the respective steam cylinders, and has legs 2 for supporting the casting on spaced skids 3.

The fluid cylinders may be separately cast as shown, and are connected by a common fluid suction manifold 4 therebeneath, and to common fluid discharge manifold 5 thereabove, the latter having a central outlet 6. Said suction manifold l is provided with legs I for supporting the assembled fluid end on the skids 3.

Steam end A and fluid end B are connected by an intervening bed portion 8, including trough portions immediately beneath the piston rods D1, D2 and D3, respectively connecting the pistons in the steam and fluid cylinders. As illustrated, the pump virtually constitutes three single direct acting steam pumps having steam chests, fluid chests, steam and fluid pistons, fluid valves, etc., of well known construction. For simplicity, these various standard elements of direct acting steam. pump mechanisms are not specifically described herein, since they are readily understood by those skilled in the art.

Our invention is particularly directed to a double acting multiple cylinder pump, characterized by the timing, operation and performance of such a multiple pump, and having to do with a novel valve gear therefor. In its preferred illustrated form, our invention is embodied in a triplex pump constructed and operated in the manner hereinafter set forth. I

One important feature of our invention resides in the overlapping of the strokes of the multiple pump so as to obtain proper timing and a high degree of smoothness of operation, thereby reducing pounding and maintaining a constant fluid pressure on the discharge side of the pump. To accomplish these results, the stroking takes place in regular sequence proportionate to the number of cylinders, i. e., the strokes of the three pistons of the triplex pump are spaced one-third of a double or complete stroke, or two-thirds of a single or half stroke apart. Thus, as one piston starts its forward or pumping stroke, one has completed two-thirds of its forward pumping stroke, and the other has traveled one-third of its return suction stroke. 4.)

To attain such Operation, we have provided a positive acting steam valve gear having no lost motion, thereby insuring perfect timing, said valve gear providing a quick full opening of the respective steam valves and enabling full opening thereof for a large proportion of the stroke. The desired eflicient and positive valve motion is provided by a compound motion applied to each valve, partially from the motion of a preceding steam piston or single engine, and partially from the motion of its own steam piston or -engine, the compound motion enabling the production of a proper return lead or advance for the valve, thereby eliminating the delay or pause upon reversal of the stroke of the piston.

The valve gear linkage is centrally mounted between the steam and fluid ends of the pump and includes a shaft assembly extending transversely of and above the piston rods consisting of nested or telescoped individually rotatable shafts, one for each engine unit. Thus, E1, E2 and E3 designate said shafts, E3 being the innermost through shaft, and shafts E1 and E2 being journaled thereon. The latter shafts are rotatably supported in suitable bearings 9 mounted on the bed portion 8 of the pump.

The valve linkage for each engine includes main levers L1, L2 and L3, main cranks M1, M2 and M2, and auxiliary links or levers X1, X2 and X3 interrelated and operable in the following manner. Each main lever is suspended from the shaft as sembly adjacent a piston rod and is provided with a roller I at its lower offset free terminal engaged with a yoke or spaced collars H on its respective piston rod, the latter connection imparting a rocking movement to each of the levers about the axis of the valve shaft assembly by the reciprocating travel of its rod.

Main lever L1 is secured to shaft E1, which latter extends to a point adjacent lever L2 and is provided with a main crank M2 extending upwardly above the shaft assembly, said crank be ing rotatable by lever L1 through said shaft E1.

Main lever L2 is secured to shaft E2, and the latter mounts upwardly extending main crank -M3 adjacent lever L2 for actuation of said crank by the lever L2. Similarly, main lever L3 rotates shaft E2 having main crank M1 rotatable therewith and positioned adjacent main lever L1.

Auxiliary links or levers X1, X2 and X3 extend between and directly interconnect the respective main levers and cranks, the same having pivotal connection I2 with the main cranks and sliding connection with the main levers, the latter connection consisting of a roller l3 mounted on the main lever and a slide [4 on the auxiliary link or crank. The auxiliary links or levers X1, X2

(See position No. 1 in Cal and X3 are offset or goose-necked as shown, to

afford clearance about the shaft assembly during the motion of the valve gear or linkage.

The compound motion thus imparted to the auxiliary links is transmitted by the latter to the steam valves V1, V2 and V3 through connecting valve rods 15 pivotally connected to the auxiliary links at IS, the pivotal connections is bein spaced above the connections i2, thereb provid ing lever arms by which the auxiliary links X1, X2 and X: are independently rotatable with respect to the cranks M1, M2 and M3.

e o sai valves is illustrated at V1 in Fig. 2, as a cylindrical valve coacting with steam admission ports I! supplied from the manifold G by suitable supply ports l8. Exhaust ports l9 are also controlled by the valve by an undercut central portion 20 to establish communication between said ports and a common exhaust outlet 2 I.

In operation, valve V1 is actuated by the movement of the main crank M1, the latter being actuated from piston rod D3, by lever L3 and shaft E3, and the auxiliary link X1, which movement is imparted by lever L1, which in turn derives its motion from the piston rod D1, the compound motion resulting therefrom being imparted through said valve rod to said valve [5. Valve V2 is actuated by main crank M2, actuated by piston rod D1, lever L1 and shaft E1, and from the link X2, whose movement is imparted by lever L2 from piston rod D2, the resulting motion being transmitted to the valve V2. Similarly, valve V: is actuated by the main crank M3 actuated by the piston rod D2, lever L2 and shaft E2, and from the auxiliary link X2, actuated b the lever La from piston rod D3, the resulting motion being transmitted to the valve V3.

The operation of the steam valves by said valve gear is clearly shown in Fig. 4, illustrating four positions for each valve and valve gear during the forward pumping stroke or one-half complete stroke of the piston in steam cylinder A1, and showing the corresponding positions of the valves of cylinders A2 and A3 and their mechanisms. In such figure, the valves V1, V2 and V3 and their admission and exhaust ports appear on an enlarged scale immediately abov the schematic showing of their respective valve gear positions.

Referring to the diagrams for cylinder A1, it will be seen that the piston rod D1 is starting its forward motion from left to right, and valve V1 is opening the left-hand admission port I! and right-hand exhaust port l9, by movement of said valve in the same direction. As shown in the lower left-hand figure of the series, rod D3 is on its return stroke, giving the position of its main lever 113 which is represented in dotted lines in the diagram for position No. 1 of engine or cylinder A1.

Continuing to position No. 2 for A1, the levers L1 and L3 are moved toward each other, and combine to move X1, opening valve V1 to admit steam to the left end and exhaust from the right end of cylinder A1, and as levers L1 and La move away from each other, as from position No. 2 to No. 3, the valve is maintained in full-open position. The admission and exhaust of the steam is shown in Fig. 4 by full and dotted line arrows at the proper ports.

At the start of the forward stroke of the piston in A1, position No. 1, the pivotal connection I2 and sliding pivotal connection [3, [4 of auxiliary link X1 with crank M1 and lever L1 respectively, are all located at one side of the common axis of rotation of the linkage, and in moving from said position to position No. 3, the linkage reverses so that said connections are on the opposite side of said axis, the reversal of the linkage being due to the opposite travel of the pistons in A1 and A3 and their respective levers L1 and L3. The combined movement of crank M1 and lever L1 effects a positive and rapid displacement of the link X1 to move the valve V1 to open position as shown.

, From positions No. 3 to No. 4, the pistons in cylinders A1 and A3 are traveling in the same direction, and link X1 is rotated by the substantially identical movement of levers L1 and Lo in reverse direction to close the valve V1, from which latter position, the linkage operates as before but in a reverse manner to admit steam to the righthand end of the cylinder A1 andexhaust from the left end for a returnstroke, as will be readily understood. 7

Attention is particularly directed to the valve gear motion taking place during the closing of the valve. The valve is moved to close its ports just prior to the completion of'the piston stroke, and during the final increment of said stroke, the corresponding travel of lever L1 imparts a final return movement to the valve through auxiliary link X1 by slight positive rotation of said link about its pivotal connection 12 with the crank M1, to move the valve in the direction of its next movement in readiness for immediate admission of steam upon the completion of the piston stroke in order to enable an immediate reversal of said stroke. In other words, the valve gear thereby receives a positive return motion from the travel of its own piston to place said valve in readiness for admission of steam instantly When the piston reaches the end of its stroke to insure the immediate reversal of said stroke.

The remaining diagrams of Fig. 4 show the respective valve linkages in their proper time and positional relation, together with their valve positions, whereby the plurality of engines or cylinders are operated in sequence, each following and overlapping the others in regular sequence spaced one-third of a complete stroke (forward and return) apart. The ultimate valv motion imparted to each valve by the auxiliary links or levers X1, X2 and X3 is compounded from the motion of the main cranks M1, M2 and M3, each actuated by the piston motion of the engine or cylinder preceding the respective engine in sequence, and by the motion of the'respective main levers L1, L2 and L3. The latter motion supplies the desired return of the valve prior to the completion of its piston stroke for immediate reversal of the latter.

Our new valve gear has no lost motion and therefore enables perfect timing. A multiple engine or pump so timed and controlled will not get out of time, and can be started from any stopped position. Due to the advance partial return motion of the valves at the ends of the strokes, the timing of the opening of the valves is improved so that a resultant smooth action of the pump is obtained. For example, in the event of a variation in the load on one engine, as by friction, valve failure, piston failure, etc., in the fluid end, tending to either speed up or retard one engine, since the valve gear or mechanism is interconnected in sequential relation, the retardation or acceleration will be opposed by each successive engine, thereby adjusting the multiple engine to the change. Corresponding operating variations in other engines or pumps, such as the duplex pump, cause short stroking and may even throw the same out of time. Such undesirable stroking is substantially eliminated in the present engine by this type of valve control.

Our invention has enabled the construction of a heavy duty pump capable of delivering large ,volumetric capacity at high pressure without compounding and having smooth uniform. operation without pounding and discharge pressure variations, generally attendant upon severe and varying load conditions. For example, a triplex pump embodying our invention has been successfully operated in the oil fields for pumping mud" steam pressure of 300 lb. per square inch. Re-

peated tests have shown that the said pump will operate at a working pressure of from to of its stalling pressure.

It has been found that the lag or delay at reversal of stroke has been substantially eliminated, and that the pump strokes substantially to full length regardless of pressure and speed.

Heretofore, it was necessary to compound two duplex pumps in order to obtain sufficient capacity to pump mud under the heavy load conditions encountered in deep well drilling, said pumps being employed in tandem, and in addition to being expensive, were subject to short stroking under the varying conditions encountered in actual service. The multiple pump of our invention is more economical, more positive, and by comparison with an equivalent pair of duplex pumps, is considerably more portable and,

easier to operate in the field. The 18x20 triplex pump as built, has an'over-all length less than regular pumps having a 20-inch stroke, the length including skids is 12-feet 7-inches, and its width is Y-feet ll-inches. Weighing 31,550 lb., this pump can be moved on the highways without any dismantling and without securing a special permit.

While we have shown and described our invention embodied in a mud or slush pump, we do not desire to be limited thereto, since the invention may be similarly embodied in other power apparatus,

Various changes and modifications are contemplated within the scope of the following claims.

We claim:

1. In a triplex direct acting steam engine or the like including three steam cylinders and valves therefor, a piston in each cylinder, a valve gear interrelating said pistons for stroking thereof in sequence with overlapping strokes spaced apart one-third of a complete stroke, said valve gear including for each cylinder and its piston, a pivotal lever actuated by the stroking of the piston, a pivotal crank, a link connected with the respective valve, lever and crank, said link comprising a direct pivotal connection between said lever and crank, shafts interconnecting the levers and cranks, one shaft connecting the crank of the first cylinder with the lever of the third cylinder, one shaft connecting the crank of the second cylinder with the lever of the first cylinder, and another shaft connecting the crank of the third cylinder with the lever of the second cylinder, whereby the links and valves are actuated by the compounded motion of their respective pistons and of the pistons preceding the same in sequence.

2. A steam valve gear for a multiple cylinder and piston direct acting engine or the like including a pivotal lever actuated by the stroking of one of said pistons, a rotatable shaft, a crank secured thereto adjacent the lever, a second lever rotatable with the shaft and actuated by the tion by the stroking of the piston, a crank rostroking of a second piston, a valve actuating link extending between and directly connecting the crank and the first lever, and being pivotally connected to said crank and lever, and a valve rod pivotally connected to the link in spaced relation to the pivotal connection of the latter with the crank.

3. A steam valve gear for a multiple cylinder and piston direct acting engine or the like including a valve actuating linkage for each piston, each linkage including a lever pivotally mounted with its axis of rotation spaced from its piston axis and depending toward the latter for actuaopposite side of the lever axis, said crank being tatable with said lever and extending on the disposed adjacent the lever of another of said linkages, a link pivotally connected to a crank of one linkage and having pivotal sliding connection with the lever of another of said linkages, said connections with the crank and lever being on opposite sides of the said lever axis, and a. valve rod pivotally connected to the link in spaced relation to the pivotal connection of the latter with the crank.

WILLIAM J. REDMAN.

JOHN M. SHIMER. 

